Burke s goldfields (lasthenia burkei labu) and contra costa goldfields (lasthenia conjugens laco) are two closely-related, winter annual plant species that occupy vernal pool wetlands in the BAY delta…

The U.S. Department of the Interior's Fish and Wildlife Service awarded a $442,709 Cooperative Endangered Species Conservation Fund (CFDA 15.615) Project Grant to the California Department of Fish and Wildlife (CDFW) to support research on the Burke's goldfields (Lasthenia burkei) and Contra Costa goldfields (Lasthenia conjugens) plant species. The 3-year project, which began on February 1, 2024, aims to: (1) evaluate seed production, quality, viability, and dormancy rates; (2) assess seed persistence in the soil seed bank under varying precipitation conditions; and (3) characterize the genetic diversity of these two endangered plant populations. The research will help inform effective seed collection, storage, and translocation strategies to establish new self-sustaining populations and preserve the remaining genetic diversity of these species, which have experienced substantial habitat loss and fragmentation in the Bay Delta region of northern California.

Burke s goldfields (lasthenia burkei labu) and contra costa goldfields (lasthenia conjugens laco) are two closely-related, winter annual plant species that occupy vernal pool wetlands in the BAY delta region of northern california. Extreme habitat loss, fragmentation, and degradation have reduced each species to 35 extant populations, with an additional 1-2.5 of vernal pool habitat lost per year in the core of each species range. With the remaining habitat under pressure due to ongoing agricultural and urban expansion, the recovery of these species is expected to require collecting and moving seeds from existing populations into areas where new pools have been constructed or previous populations have gone extinct. If successful, these translocated seeds would establish new, self-sustaining populations that increase overall species numbers and preserve the remaining genetic diversity of each species. In this project, doctor (DR.) nancy emery and DR. Ezra kottler from the university of colorado, boulder (CU boulder), aim to address several high-priority research actions for labu and laco to improve the success of seed translocation efforts for these species. The primary goals of this project are to (1) evaluate seed production, quality, viability, and dormancy rates in multiple populations and growing seasons, (2) assess the potential for seeds to persist in the soil seed bank over multiple growing seasons and under different precipitation scenarios (i.e. drought, flood), and (3) characterize the genetic diversity of populations across each species range and over multiple growing seasons. To accomplish these objectives, the researchers will measure seed germination and dormancy in incubator studies of field-collected seeds, conduct a greenhouse study to measure seed germination responses to different soil moisture conditions, and complete the broadest genetic analysis to date of each species. All activities will include individuals that will be sampled from different populations, natural and created pools, and different years to quantify site-to-site and year-to-year variation in all measurements. The agency partners, nicholas wagner (california department of fish and wildlife cdfw , BAY delta region) and vincent griego (united states fish and wildlife USFWS , sacramento field office) will advise and support all aspects of this project. The proposed research addresses several priority research tasks actions for each species that include: measuring seed set, seed viability, and seed germination conditions, characterizing the seed bank, describing the amount and distribution of genetic variation to inform seed introductions and reintroductions, and determining management strategies that can mitigate the negative effects of climate extremes (e.g., drought, flooding) and invasive species on the focal taxa. The products of this work will include annual and final reports to the cdfw, publications in scientific journals, and seed donations to the california botanic garden that will supplement existing collections of each species in long-term storage. Results will be used to advance the development of effective, evidence-based guidelines for the collection and distribution of seeds to support the recovery of these two endangered plant species.